I've got a Silencerco Sparrow silencer in jail waiting for the ATF to release it to me.

Got a threaded barrel Ruger Mark III for it, and also I'd like to hook it up to my
15-22. I'm wondering if the stock barrel threading on the rifle is the proper lengty for the silencer or whether I will need a washer of some sort.

Also, I'd appreciate known what ammo works best in the rifles in terms of proper cycling and quietness. CCI Standard Velocity is what I am planning to use...and I know a lot of subsonic ammo will not cycle the action properly.

What are your recommendations?

I have a .22 Compact and Sparrow. It took a specific adapter, as the sparrow uses an o-ring engagement. That means a bit of the end of the adapter would not be threaded. An alternative is to use a spacer, but you'll have to sort out the size.

Silencerco makes an adapter that just adds a threaded part with clean shoulder. I have not yet put it on my 10/22, but that will probably require one of the two (addition adapter or spacer).

You can look at Silencerco's site for pics that will explain it better than I did.

I've used that combination with CCI standard velocity with no issue. Have not tried other ammo yet.

You must use the spacer. Google it & you will find them around. On my last 15-22, I sent the barrel to Adco & had them cut off the old threads & re-thread for the proper length & for the o-ring engagement. Since the barrel is a bit over 16" long, you can do so & still stay legal.

I shoot CCI Sub Sonic, CCI Standard Velocity & Norma Tac-22. All cycle perfectly. I am a big fan of the Norma & it has been available by the case.

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FIDELITAS ET FORTITUDO

Gemtech has some nice ammo

CCI standard is fine. Doubtful that the "quiet" ammo is any quieter out of a rifle barrel. I noticed a slight difference in my suppressed pistols but prefer the CCI standard as it is more common and economical to buy when you can find it.

Actually quiet is a lot quieter in the 15-22 or even a bolt rifle. I have a post about a week ago seeing if anyone had found a combo to make the 15-22 cycle on quiets, that is going to be my next project.

Cci std velocity no problem, it's been my go to ammo so far, I should try Norma tac also just to see if it is quieter

My 22/45 Lite works fine with Federal bulk from WallyWorld (as does my custom 4-1/2" SBR upper which was built to host the Sparrow SS).

I use Norma Tac22 exclusively for the reasons Jim stated above. I use it through my Sparrow and Warlock. No trouble cycling a 10/22, an SBR 15-22, an M&P 22 Compact or a Walther P22.

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M&P's and K Frames Pleeze!

P.S. my Sparrow came with a spacer...

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M&P's and K Frames Pleeze!

The CCIs work flawlessly - Standards are all I use in my 15-22 and .22 pistol and apart from a few FTFs from the pistol (which have worked immediately when put back into the 15-22) they've been faultless.

I've toyed with the AR Tacticals and Mini-mags but can't see why I would...

I have a Sparrow on my Ruger 22/45. I use American Eagle subsonic. Muzzle velocity 970 FPS. Pretty quite and feeds well. Plus, I like the fact that it is plated.